Abstract: DECODING ADC ANALOG LPF × cost Figure 9.3 The TX input serial bit stream is first , real part of the QAM modulator and one for the imaginary part. As an example, a diagram of a 16 , antialiasing filter and ADC, a demodulator, an adaptive equalizer, a Viterbi decoder, an echo canceller, a , . The antialiasing filter and ADC in the receiver need to have a dynamic range from the largest echo , constellation with no imaginary component, i.e., the analog modem receiver must detect which one of the 256

Abstract: sampled waveform. A Low Pass Filter (LPF) is used FOUT = (1 Hz/27) * to reduce these image signals , LPF should be then FOUT = 1 Hz equal to or less than half the sample frequency. If we choose , The specifications of the DAC, LPF design, and determined by the following formula: Frequency , of the system, even the quality of the DAC and the LPF design as well as though its effect is , clock frequency and FOUT is the on the slope of the roll off of the LPF determine the generated